1. Field of the Invention
The invention relates to grounding devices for use with shielded DIN connectors, particularly to the grounding plate which can be reliably retained with the corresponding DIN connector and thus be efficiently engaged with the shield of such DIN connector for ESD (Electrostatic Discharge) or EMI (Electromagnetic Interference) consideration.
2. The Prior Art
Din connectors are very popular I/O (Input/Output) components for use with the computer. For aforementioned ESD and/or EMI consideration, most recent DIN connectors are covered by the shield which optimally surrounds four side faces and a top face, except the bottom face which is directly mounted onto the PC board, of the connector housing. For a common design, a conductive path is formed between such shield and the below PC board for removal of the undesired electrostatic charges from the shield to the grounding electrode printed on the PC board. While, sometimes a grounding device which is designedly connected between the shield of the DIN connector and the backpanel of the computer wherein such DIN connector is positioned closely disposed behind the backpanel and can mate with an external complementary plug connector via an opening in the backpanel. It can be understood that the grounding device may be deemed as an auxiliary grounding means for promptly removing any improper electrostatic charges imposed on the shield of the DIN connector therefrom through the backpanel and the computer case, instead of the conventional path, i.e., through the circuits which are printed on PC board and directly connected to the grounding legs downward extending from the shield of the DIN connector.
To assure a good conduction between the shield of the DIN connector and the backpanel, such grounding device therebetween is generally required to be characterized to own sufficient resiliency for provision of desired engagement with the corresponding shield of the connector and the corresponding backpanel of the computer case. Additionally, because such grounding device is generally arranged as an optional accessory of the DIN connector and may be provided therewith if requested by the computer manufacturer, the grounding device should have a reliable retention relationship with the DIN connector for not jeopardizing its integrity with the DIN connector regardless of whether it is during delivery from the connector manufacturer to the computer manufacturer, or it has been assembled in the computer and sold to the end user. Good retention of the grounding device with regard to the DIN connector assures that the grounding device can not be dropped from the DIN connector not only during shipping from the connector manufacturer to the computer manufacturer for simplifying assembling such DIN connector associated with the corresponding grounding device to the whole computer set, but also after such DIN connector with the grounding device has been assembled to the computer whole package and used by an end user for expectation of the excellent grounding function occurring between the shield of the DIN connector and the backpanel of the computer case.
Most prior art grounding devices are as shown in FIG. 1 which uses two screws 3 extending through two corresponding holes (not shown) in the connector 1 for fastening the grounding device 2 to the connector 1 and achieving the conductive path formed between the grounding device 2 and the front shell 4 of the connector 1. Even though the retention and electrical engagement of the grounding device 2 regard to the connector are without question, the disadvantage of this type design includes (1) more components, i.e., screws, being used for implementation of assembling of the grounding device 2 and the connector 1. Therefore, a second type prior art grounding device was introduced in U.S. Pat. No. 5,288,248, which has the same assignee with the invention wherein the grounding device includes two hook sections adapted to extend around the bottom edge of the front shell of the DIN connector and further latchably project into two corresponding recesses located on two opposite front bottom corners of the housing. This configuration may eliminate using two fastening screws of the first type design, but sometimes the recesses can not securely retain the corresponding hook sections of the grounding device 2 therein. Thus, the grounding device may be easily dropped from the DIN connector during shipping from the connector manufacturer to the computer manufacturer, and the worker of the computer manufacturer needs to take more care of assembling the connector with the grounding device to the whole computer system. By the way, such questionable retention between the grounding device and the connector may introduce a poor engagement therebetween, accordingly. Then, the grounding performance of such grounding device may be diminished.
Accordingly, an object of the invention is to provide a DIN connector with a grounding device which is adapted to be not only easily attached thereto, but also securely retained thereto, thus assuring no dropping during delivery and good conductive engagement therewith for achievement of desired ESD and/or EMI consideration.